Art of rolling sheet metal



July 22, 1930. A. PATERSON 1,770,993

ART OF ROLLING SHEET M TAL Filed Oc t. a, 1927 2 Shets-Sheet 1 July 22, 1930. A. PA' IERSQN 1,770,993

I ART OF ROLLING SHEEET METAL 1 Filed Oct. 6, 1927 2 Sheets-Sheet 2 I 2161611 4673113? m'on gwms w Patented July 22, 1930 UNITED STATES.

PATENT OFFICE ALEXANDER PATERSON, 02E BUFFALO, NEW YORK ART OF ROLLING SHEET METAL I Application filed October 6, 1927. Serial No. 224,343.

5 cross section and in a method of producing rolled sheets in which the preforming of the pack, as hereafter described, is an essential step.

The principal objects of the invention are i to provide for packs having a standardized or uniform convex cross section without re gard to the original cross sect-ion of the part or parts of which the pack may be composed,

- to avoid limitations imposed by I the pack forming method heretofore employed, both as to the class of labor required and as to the number of sheets in a pack, to reduce the liability of producing defective packs and to decrease the frequency of finishing roll replacement.

' Other objects are to eliminate the neces-;

sity of varying thespecial turning of the finishing rolls in order to meet the requirements of packs produced by various mills, to

utilize to advantage an action of the rolls 1 heretofore regarded as disadvantageous and to reduce the cdst both of forming the pack and its subsequent rolling.

The invention is directed to the formation of packs having a uniform convex cross section (by which is meant a cross section of greater thickness at its center or in a central section than elsewhere) from metal variously known as sheets, strip sheets, sheet bars, plates, break-downs, etc., the cross section of which always varies with the particular mill in which the part is rolled, and to the combination of this'special pack-forming ste with the subsequent rolling of such packs to nished gauge. For purposes of illustration the metal will be referred to as sheets or as packs made of two or more sheets but it is to be understood as comprising any oftheabove mentioned terms or their equivalent.

Due to the necessity of separating the sheets comprising a pack of metal after the pack has been rolled, the rolling condition must be such as will'insure an even longitudinal flow of metal. It has. long been known that the desired even longitudinal flow may be obtained by reducing a metal pack on rolls having their factors so determined as to reduce the center thickness of the pack slight- .ly more than the side thicknesses, but this has required careful adjustment of the rolls as regards deflection, screw, stretch of housings,

. etc. for each pass in connection with a numwhich as utilized to form a pack containing two or more layers and permits the economical production'of comparatively high gauge sheets and avoids the objection of doing the breakdown work in the finishing rolls. Other objects are attained by a novel method of rolling such pre-formed packs which will permit the use of finishing rolls as heretofore generally used and which will utilize the deflection of the roll centers incident to the successive reductions of the pack for the purposes of controlling the roll passes and advantageously ordering the reductions.

The invention is illustrated in the accompanying drawing, in which Figure 1 is a perspective view of a strip of sheet metalwhieh has been slittcd and partially folded.

Figures 2, 3, and 4 are diagrammatic views showing a pack and forming rolls at various formed pack.

Figure 6 is a diagrammatic view of a series of finishin' rolls.

Figures 8, and 9 are exaggerated cross sectional views through the finishing rolls of Fig; 6, showing the paekat these various stages.

In carrying out the present invention, I preferably utilize a substantially rectangular'pack as disclosed in my prior Patent No.

T l-1,708 and dated October 20, 1903, in which a strip of sheet metal 1 is transversely slitted at various points 2 along its length, the number of slits depending on the number of layers desired and the distance between slits depending on the width'of the-sheet desired. These slits may extend the width of the strip but are preferably made to extend partially across so as to leave a web of metal 3 connecting adjacent sections. The sections are then folded one over the other so as to form a multi-layer pack and pressed together to facilitate its manipulation.

The pack is given a convex cross section by anyone of a'variety of shaping devices.

.- For instance, in Figures 2, 3, and 4 I have illustrated a shaping device at various stages of the forming operation comprising a pair of eccentric co -operating rolls 4, each of which has a portion of its roll surface cut away, together with an adjustable stop gauge 5. In operation the gauge is set at the proper distance and while the rollsare in a position where their cut away portions define the pass, the pack is passed laterally between them until it strikes the stop gauge as shown in Figure 2 whereupon the continued; rotation of the rolls moves the pack away from the stop (see Fig. 3). As the rolls rotate, their eccentric surfaces compress the metal of the pack from the center toward one side with increasing pressure and thereby reduce the. pack transversely toward said side. In this manner one side of the pack is formed so that its. thickness gradually decreases from the cen ter toward such side, The shaping or convexing of the pack is completed by a similar treatment of the other side and the completely formed pack is shown in Fig. 5. The shaping of the pack in this manner may be, and preferably is, effected with a cold pack. By proceeding in this manner various packs produced by various mills may be formed with a uniform convex cross section, regardless of the cross section they or their parts may have originally had as a result of being rolled in a particular mill. This uniform convex cross section may be determined as desired and as so determined will be a standard cross section to which the setting of the various mills'in which the different packs may be finished will conform. Obviously in choosing a standard cross section there will be a selection of the thickness of the pack and the degreeof convex curvature and either or both may be altered if it is desired to change to a new standard or'to have more than one standard.

The pack after being thus formed may either be immediately reduced or it may be shipped as an article of manufacture in which case the final reduction is completed elsewhere. In any case the reduction must be carried out in the manner described heretofore, that is to say the central portion must be reduced more than the side portions in each pass, but the reduction is essentially a final rolling and the greater part of the ex eusive preparatory and intcrn' ediate manipuation with skilled labor heretofore require is eliminated,

' In order to reduce the pack in the abo' e manner, I preferably utilize a series oi stands (3, 7, and 8 asshown in Figure 6 in which the roll diameters progressively in-- crease, each roll being turned with a slight concavity in order to compensate for its expansion when heated, this latter treatment being the usual practice. By this arrangement, the convexity of the active passes progressively decreases (see Figs. 7, 8, and 9) inasmuch as the deflection of the roll centers is inversely proportional to their diameters, all other things being comparatively equal. Thus when a pack of metal (which has first been heated to a suitable temperature) is passed through the rolls, the roll centers of the first stand 6 will be deflected a certain amount, of the second stand I a smaller amount, and so on to the last stand 8 and in thismanner the center thickness is made gradually to approach the side thicknesses. The same result may be obtained by utilizing a series of stands in which the roll lengths progressively decrease, the diameters of the rolls in such case being equal. \Vhile I have shown three stands in Figure 6, it is to be understood that a greater or lesser number of stands may be utilized as desired, and that the pack may, if desired, be reduced by an ordinary single strand mill (for which it is suitably cross sectioned as above described) by repeated passes and suitable adjustments of the screw for each pass. The standard crosssection of the pack having been determined as above explained, the mill, in any case, is set with reference to such standard and to the thickness of the sheet which it is desired to roll and thereupon is available without further adjustment for the final rolling of all packs conforming to such standard. If any change in the cross section of the pack to a new standard be made and which does not involve a change in the convex cross sectional curvature the necessary re-adjustment of the mill to conform to the new standard I may bemade without, however. entailing any change in the turning of the finishing rolls.

The shaping of the pack as before related may be accomplished in a number of ways which'are applicable to cold working. For

instance the pack can readily be shaped by an eccentric toggle arrangement, or by means of eccentric rolls designed to completely shape a pack in one movement it passes between them. It is obvious that an arrange ment operating like the last mentioned rolls, may be used to form a pack composed of a number of strips with a series of waves which could then be cut to form'a number of individual packs.

I claim as my invention:

1. A sheet metal pack preformed as a standard article of manufacture for final rolling by reduction from its longitudinal center outward to its sides, thereby to have a predetermined cross sectional area and a predetermined convex-cross sectional curvature for which the mill which .eifects thefinal rolling is given a. predetermined adjustment.

2. A sheet metal pack composed of at least two layers and preformed as a standard article of manufacture for final rolling by reduction from its longitudinal center outward to its sides, thereby to have a predetermined cross-sectional area and a predetermined convex cross-sectional curvature for which the mill which effects the final rolling is given a predetermined adjustment.

As a standard artlcle of manufacture a sheet metal pack towhich in preparation.

for final rolling is imparted a convex cross section conforming as to area and outline to a predetermined standard for which the mill which effects the final rolling is given a predetermined adjustment.

4. As a standard article of manufacture a sheet metal pack composed of at least two layers and to which in preparation for final rolling is imparted a convex cross section conforming as to area and outline to a predetermined standard for which the mill which effects the final rolling is given a predetermined adjustment.-.

The method of shaping a sheet metal .pack prior to and in preparation for final rolling, consisting in forming the. pack with a predetermined standard cross sectional area having a predetermined convexity of outline for which the mill which efiects the final roll-' ing is given a predetermined adjustment.

6. The method-of shaping a sheet metal pack prior to and in preparation for final rolling, consisting in cold forming the pack with a predetermined standard cross sectional area having a predetermined convexity of outline for which the mill which effects the final rolling is given a predetermined adj ustment'. d

7. The method- 0f shaping a sheet metal pack prior to and in. preparation for final rolling consisting in forming the pack first on one side and then on the other side of its longitudinal center line with a cross section of predetermined standard area and predetermined standard tapering outline toward its edge for which the mill which effects thefinal rolling is given a pre etermined adjustment.

standard cross sectional area and predetermined standard convex curvature for which the mill which effects the final rolling is' given a predetermined adjustment.

9. The method of rolling sheet metal con-- ing said pack by successive roll passes having their adjustment predetermined with ref erence to said standard cross-sectional area and said standard cross-sectional outline and in which the deflections of the roll centers progressively decrease.

' 1-1. The method of rolling sheet metal consisting in shaping a pack to a predetermined standard cross-sectional area and a predetermined standard cross -sectionally convexoutline and subsequently passing said pack through a series of reducing stands having a predetermined adjustment with reference to said standard cross-sectional area and standard cross-sectionaloutline and in which the roll diametersprogressively increase.

In testimony whereof I afiix my signature. I

ALEXANDER PATERSON.

8. The method of shaping a metal pack prior to and in preparation for final rolling consisting in reducing the pack transversely between its longitudinal center and its sides, thereby forming the pack of predetermined 

